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Vol. 45 - N. 2 SUPPLEMENT Bollettino di Geofisica teorica ed applicata An International Journal of Earth Sciences Guest Editors: J. Carcione, F. Donda, E. Lodolo International Symposium on the Geology and Geophysics of the Southernmost Andes, the Scotia Arc and the Antarctic Peninsula Extended Abstracts of the GeoSur2004 International Symposium 22-23 November, 2004 Buenos Aires, Argentina Istituto Nazionale di Oceanografia ISSN 0006-6729 e di Geofisica Sperimentale Responsibility for all statements made in B.G.T.A. lies with the authors Cover design and typesetting: Nino Bon – OGS Printing: Centro Box SRL – Buenos Aires, Argentina Authorized by the Tribunale di Trieste, n. 242, September 17, 1960 INTERNATIONAL SYMPOSIUM International Symposium on the Geology and Geophysics of the Southernmost Andes, the Scotia Arc and the Antarctic Peninsula 22-23 November 2004 Buenos Aires, Argentina EXTENDED ABSTRACTS GEOSUR2004 22-23 NOVEMBER 2004 – BUENOS AIRES ORGANIZERS ISTITUTO NAZIONALE DI OCEANOGRAFIA E DI GEOFISICA SPERIMENTALE - OGS, TRIESTE, ITALY INSTITUTO DE GEOFÍSICA “DANIEL A. VALENCIO”, DEPARTAMENTO DE GEOLOGÍA, UNIVERSIDAD DE BUENOS AIRES, ARGENTINA SPONSORS ITALIAN EMBASSY IN ARGENTINA PROGRAMMA NAZIONALE DI RICERCHE IN ANTARTIDE (P.N.R.A.) EAGE-SEG Italian Section 4 GEOSUR2004 22-23 NOVEMBER 2004 – BUENOS AIRES SCIENTIFIC COMMITTEE G. BRANCOLINI - OGS, Trieste A. CAMERLENGHI - OGS, Trieste M. CANALS - University of Barcelona J.M. CARCIONE - OGS, Trieste A.H. COMÍNGUEZ - CONICET, University of La Plata I.W.D. DALZIEL - University of Texas at Austin E. DOMACK - Hamilton College, New York F. HERVÉ - University of Santiago R. LARTER - British Antarctic Survey S. MARENSSI - IAA, Buenos Aires G. PANZA - University of Trieste C. PARICA - CONICET, University of Buenos Aires V. RAMOS - University of Buenos Aires A. RAPALINI - INGEODAV, University of Buenos Aires G. RÉ - INGEODAV, University of Buenos Aires C. RODA - University of Udine M. RUSSI - OGS, Trieste D. VELIS - University of La Plata ORGANIZING COMMITTEE J.L. HORMAECHEA - EARG, Rio Grande H. LIPPAI - INGEODAV, University of Buenos Aires E. LODOLO - OGS, Trieste M. MENICHETTI - University of Urbino S. PERSOGLIA - OGS, Trieste J. RABASSA - CADIC, Ushuaia R. SEMENZATO - Italian Embassy, Buenos Aires A. TASSONE - INGEODAV, University of Buenos Aires J.F. VILAS - INGEODAV, University of Buenos Aires CONFERENCE SECRETARIAT ANGELA MARCHETTO - EAGE-SEG Italian Section 5 CONTENTS Session 1 - Regional Geology LATE JURASSIC BIRTH OF THE ROCAS VERDES BASIN AT THE SARMIENTO OPHIOLITIC COMPLEX: EVIDENCE FROM ZIRCON U-PB SHRIMP GEOCHRONOLOGY . 1-01 M. Calderón, F. Hervé, C.M. Fanning THE ITALIAN CONTRIBUTION TO THE DEVELOPMENT OF THE GEOLOGIC KNOWLEDGE OF ARGENTINA . 1-02 H.H. Camacho DEEP-SEISMIC IMAGING ACROSS LOS CHIHUIDOS ARCH, NEUQUEN BASIN, ARGENTINA (38° SL) . 1-03 A.H. Comínguez, J.R. Franzese REFLECTIONS ON THE SCOTIA ARC AT ITS CENTENNIAL . 1-04 I.W.D. Dalziel AEROGEOPHYSICAL IMAGING REVEALS A COMPOSITE TERRANE OVER PALMER LAND (ANTARCTIC PENINSULA) . 1-05 F. Ferraccioli, P. Jones, A.P.M. Vaughan, A. Dean, P.T. Leat THE CARIBBEAN PLATE CURRENT PROBLEMS: AN EXAMPLE FOR EVOLUTION OF SMALL PLATES . 1-06 G. Giunta THE WEST-DIRECTED SUBDUCTION ZONES OUTSIDE OF THE PACIFIC: SCOTIA, CARIBBEAN, TYRRHENIAN AND CARPATHIANS DOMAIN . 1-07 M. Guidarelli, O. Gonzalez, R. Raykova, T. Pinat, G.F. Panza NORTHERN ANTARCTIC PENINSULA – SOUTHERN PATAGONIA: A PRELIMINARY STRATIGRAPHIC FRAMEWORK FOR COMPARISON OF PALEOGENE EVENTS . 1-08 S.A. Marenssi GEOMETRIES, DEFORMATION STYLES AND KINEMATICS OF THE FUEGINAN ANDES AND MAGALLANES FOLD-AND-THRUST BELT (TIERRA DEL FUEGO ISLAND) . 1-09 M. Menichetti, M. Cenni, D. Gattini, A. Gaudio, M. Mattioli TECTONICS OF THE SOUTHERNMOST ANDES: A COMPARISON BETWEEN THE PATAGONIAN AND THE FUEGIAN CORDILLERAS . 1-10 V.A. Ramos SEISMIC IMAGING OF THE MAGALLANES-FAGNANO FAULT SYSTEM (TIERRA DEL FUEGO REGION) . 1-11 D. Yagupsky, A. Tassone, E. Lodolo, M. Menichetti, J.F. Vilas Session 2 - Geodynamic and Tectonics DEVELOPMENT OF ASYMMETRIC BASINS ALONG THE MAGALLANES-FAGNANO FAULT AND OTHER CONTINENTAL TRANSFORM FAULTS . 2-01 Z. Ben-Avraham, E. Lodolo PLATE KINEMATICS OF THE ANTARCTIC PENINSULA . 2-02 R. Dietrich, A. Rülke BREAKUP OF GONDWANA AND OPENING OF THE SOUTH ATLANTIC: REASSESSMENT BASED ON MAGNETIC ANOMALIES . 2-03 M.E. Ghidella, L.A. Lawver, L.M. Gahagan CRONOLOGY OF OROGENIC FRONT PROPAGATION IN THE FUEGUIAN FOLD-THRUST BELT . 2-04 M.C. Ghiglione, V.A. Ramos, E.B. Olivero 7 CONTENTS TECTONIC AND GEODYNAMIC EVOLUTION OF THE SOUTH SANDWICH ARC AND EAST SCOTIA SEA . 2-05 R.D. Larter AGULHAS PLATEAU, MAUD RISE AND NE GEORGIA RISE, PRODUCTS OF A TRIPLE JUNCTION? . 2-06 L.A. Lawver, L.M. Gahagan SOUTH AMERICA - ANTARCTICA PLATE MOTION AND TECTONICS OF THE SOUTHERNMOST ANDES, SCOTIA SEA AND ANTARCTIC PENINSULA . 2-07 R. Livermore, G. Eagles, P. Morris, A. Nankivell SPREADING REGIME AND TECTONICS IN THE WESTERNMOST SCOTIA SEA . 2-08 E. Lodolo, A.A. Schreider GEOLOGICAL CROSS-SECTION ACROSS THE FUEGINAN ANDES IN THE TIERRA DEL FUEGO ISLAND . 2-09 M. Menichetti DIFFERENT STYLES OF CONTINENTAL GROWTH AT THE CONVERGENCE ZONE OF SOUTHERN CHILE . 2-10 A. Polonia, M.-F. Loreto, L. Torelli, E. Vera NORTHWARD MOTION OF SOUTH AMERICA, SCOTIA SEA DEVELOPMENT, AND CARIBBEAN CONVERGENCE . 2-11 R. Somoza PALEOMAGNETISM FROM UPPER TRIASSIC-LOWER JURASSIC ROCKS IN THE DESEADO MASSIF: NEW INSIGHTS ON THE BEHAVIOR OF PATAGONIA DURING THE BREAKUP OF GONDWANA . 2-12 H. Vizán, R. Somoza, G. Taylor Session 3 - Earthquake Seismology EARTHQUAKE EPICENTRES IN TIERRA DEL FUEGO FROM MAY 1999 TO MARCH 2004 . 3-01 G. Connon, L. Barbero, C. Ferrer, J.L. Hormaechea, N. Sabbione, R. Pinciroli, C. Rastelli, M.P. Plasencia Linares LITHOSPHERIC STRUCTURES AND REGIONAL SEISMICITY IN THE SCOTIA SEA AREA: A REVIEW . 3-02 M. Guidarelli, M.P. Plasencia Linares, M. Russi, G.F. Panza THE 4 AUGUST 2003 EARTHQUAKE RECORDED BY ASAIN NETWORK IN ANTARCTICA AND TIERRA DEL FUEGO . 3-03 M.P. Plasencia Linares, B.G. Bukchin, M. Guidarelli, M. Russi, G.F. Panza FURTHER DEVELOPMENTS OF THE ASAIN NETWORK IN ANTARCTICA AND TIERRA DEL FUEGO . 3-04 M. Russi, M.P. Plasencia Linares, M. Guidarelli Session 4 - Magmatic Processes DISCOVERY OF ALKALI-BASALTS IN TIERRA DEL FUEGO . 4-01 R.D. Acevedo LITHOLOGIC TYPES OF THE JEU-JEPEN DIORITE ISLA GRANDE DE TIERRA DEL FUEGO . 4-02 R.D. Acevedo, C. Roig, M.L. Valín-Alberdi IRON SULFIDES RELATED TO FUMAROLIC VENTS IN DECEPTION ISLAND, ANTARCTICA . 4-03 A.T. Caselli, S.M. Tourn, C. Bengoa 8 CONTENTS EMPLACEMENT FABRICS OF THE CONCÓN DYKE SWARM, CENTRAL CHILE . 4-04 C. Creixell, M.A. Parada, P. Roperch, C. Arriagada, D. Morata METAMORPHIC P-T CONDITIONS OF RHYOLITES IN THE MAGALLANES FOLD AND THRUST BELT, PATAGONIAN ANDES . 4-05 F. Hervé, H.-J. Massonne, T. Theye, M. Calderón MONITORING MAGMATISM OF THE PATAGONIAN BATHOLITH THROUGH THE U-PB SHRIMP DATING OF DETRITAL ZIRCONS IN SEDIMENTARY UNITS OF THE MAGALLANES BASIN . 4-06 F. Hervé, E. Godoy, C. Mpodozis, M. Fanning THE PALEOCENE–EOCENE SEJONG FORMATION, BARTON PENINSULA, KING GEORGE ISLAND, ANTARCTICA: ERUPTIVE AND DEPOSITIONAL PROCESSES AND ENVIRONMENTS . 4-07 S.B. Kim, Y.K. Sohn, M.Y. Choe, J.I. Lee, S.D. Hur IMPLICANCES OF THE ACTIVITY OF FLUOR-RICH FLUIDS ON BASALTS AFFECTED BY VERY LOW GRADE METAMORPHISM IN CHAPELCO HILLS, NEUQUÉN, ARGENTINA . 4-08 C.I. Martínez Dopico, E. Gallegos, M.E. Vattuone MAGMATIC MUSCOVITE AND GARNET IN GRANITES OF THE SOUTHERN PATAGONIAN BATHOLITH . 4-09 H-J. Massonne, M. Calderon, F. Hervé EFFECTS OF METAMORPHISM ON MAGNETIC SUSCEPTIBILITY AND FERROMAGNETIC MINERALS IN THE SARMIENTO OPHIOLITE COMPLEX, SOURTHERN CHILE . 4-10 S. Singer, A. Rapalini, M. Calderón, F. Hervé THE ORIGIN OF PLATINUM IN TIERRA DEL FUEGO: GEOLOGICAL EVIDENCE . 4-11 E. Zappettini, L. Villar, S. Segal, A. Celeda, A. Romano, D. Acevedo Session 5 - Geomorphology and Geodesy REGIONAL GEOID DETERMINATION IN TIERRA DEL FUEGO INCLUDING GPS LEVELLING . 5-01 D. Del Cogliano, R. Dietrich, A. Richter, R. Perdomo, J.L. Hormaechea, G. Liebsch, M. Fritsche HORIZONTAL DISPLACEMENTS IN THE MAGALLANES-FAGNANO FAULT ZONE DETERMINED BY REPEATED GPS OBSERVATIONS . 5-02 J.L. Hormaechea, D. Del Cogliano, R. Perdomo, R. Dietrich, G. Liebsch, A. Richter, M. Fritsche GEOID UNDULATION ON THE ANDEAN CORDILLERA . 5-03 A. Introcaso, L.E. Lenzano, A.M. Robin, M.V. Mackern MORPHO-STRUCTURE OF LAGO FAGNANO (TIERRA DEL FUEGO) AND ADJACENT AREAS . 5-04 H. Lippai, E. Lodolo, A. Tassone, J.L. Hormaechea, M. Menichetti, J.F. Vilas, TESAC Party GEODETIC DETERMINATION OF RELATIVE PLATE MOTIONS AND CRUSTAL DEFORMATIONS DUE TO SOUTH AMERICA, SCOTIA AND ANTARCTIC PLATE INTERACTIONS . 5-05 R. Smalley Jr., E. Kendrick, M.G. Bevis, I.W.D. Dalziel, F. Taylor, E. Lauría, R. Barriga, G. Casassa, E. Olivero, E. Piana, A. Zakrajsek Session 6 - Marine Geology and Geophysics MORPHOLOGY AND SEDIMENTARY PROCESSES ON THE TERRACED ACCRETIONARY PRISM OF SOUTHERNMOST SOUTH AMERICA . 6-01 R. Bartole, D. Morelli, A. Cuppari SEISMOSTRATIGRAPHY AND RECENT SEDIMENTARY EVOLUTION OF AN ASYMMETRIC EXTENSIONAL BASIN AT THEWESTERN ARM OF THE MAGALLANES-FAGNANO TRANSFORM SYSTEM . 6-02 R. Bartole, W. Colautti, E. Colizza, C. Salvi, F. Tosoratti 9 CONTENTS MARINE GEOLOGY OF THE EREBUS AND TERROR GULF REGION, NW WEDDELL SEA . 6-03 E.W. Domack, E. Backman A GEOPHYSICAL STUDY ALONG THE EASTERN MARGIN OF THE ANTARCTIC PENINSULA . 6-04 W. Jokat, V. Helm, R. Krocker SEISMIC EXPRESSION OF THE WESTERN SCOTIA SEA CONTINENTAL MARGINS . 6-05 C. Sauli, E. Lodolo, N. Wardell, A. Tassone, A. Polonia 3D CRUSTAL VARIATIONS IN THE PHOENIX-ANTARCTIC RIDGE (P2 SEGMENT) . 6-06 E. Suriñach, E.L. Flores-Márquez, J. Galindo-Zaldivar, A. Maldonado 3D MODELLING OF THE SOUTH SCOTIA RIDGE PLATE BOUNDARY (ANTARCTICA) . 6-07 S. Susini, M. De Donatis, N. Zitellini GAS HYDRATES AND ACTIVE FLUID OUTFLOW NE OF THE SOUTH SHETLAND ISLANDS, ANTARCTIC PENINSULA . 6-08 U. Tinivella, F. Accaino, R.
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    Andean Geology ISSN: 0718-7092 ISSN: 0718-7106 [email protected] Servicio Nacional de Geología y Minería Chile Geochemical characteristics of the infilling of ground wedges at Puerto Deseado (Santa Cruz, Argentina): palaeoenvironmental and chronological implications Zanchetta, Giovanni; Ribolini, Adriano; Ferrari, Matteo; Bini, Monica; Isola, Ilaria; Lezzerini, Marco; Baroni, Carlo; Salvatore, Maria Cristina; Pappalardo, Marta; Fucks, Enrique; Boretto, Gabriella Geochemical characteristics of the infilling of ground wedges at Puerto Deseado (Santa Cruz, Argentina): palaeoenvironmental and chronological implications Andean Geology, vol. 45, no. 2, 2018 Servicio Nacional de Geología y Minería, Chile Available in: https://www.redalyc.org/articulo.oa?id=173955659002 DOI: https://doi.org/10.5027/andgeoV45n2-3070 PDF generated from XML JATS4R by Redalyc Project academic non-profit, developed under the open access initiative Andean Geology, 2018, vol. 45, no. 2, ISSN: 0718-7092 0718-7106 Artículos de Investigación Geochemical characteristics of the infilling of ground wedges at Puerto Deseado (Santa Cruz, Argentina): palaeoenvironmental and chronological implications Características geoquímicas de las cuñas de hielo en Puerto Deseado (Santa Cruz, Argentina): implicancias paleoambientales y cronológicas Giovanni Zanchetta DOI: https://doi.org/10.5027/andgeoV45n2-3070 Istituto Nazionale Geofisica e Vulcanologia Roma, Italia Redalyc: https://www.redalyc.org/articulo.oa? [email protected] id=173955659002 Adriano Ribolini University
  • a Pleistocene Ice Sheet in the .' Northern Boulder Mountains

    a Pleistocene Ice Sheet in the .' Northern Boulder Mountains

    , A Pleistocene Ice Sheet in the .' Northern Boulder Mountains .< Jefferson, Powell, and Lewis and Clark Counties, Montana By EDWARD T. RUPPEL CONTRIBUTIONS TO GENERAL GEOLOGY GEOLOGICAL SURVEY BULLETIN 1141-G A descriptive report of the glacial geology in the northern part of the Boulder Mountains, Montana UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON : 1962 UNITED STATES DEPARTMENT OF THE INTERIOR STEWART L. UDALL, Secretary GEOLOGICAL SURVEY Thomas B. Nolan, Director For sale by the Superintendent of Documents, U.S. Government Printing Office Washington 25, D.C. CONTENTS Page Abstract- _______-_-______-__-_--____--___________--____-_-_-______ G-1 Introduction. _ _____________________________________________________ 1 Summary of bedrock geology.___-___-____.____._-___._.__--__--_.___ 4 Surficial geology.._________________________________________________ 5 Northern Boulder Mountains ice sheet- ___-____-___.----_-_--_-__ 5 Glacial erosion.___________________________________________ 7 Glacial deposits.-______--_^______-________________________ 9 Age and regional relations of glaciation.___:______.____________ 11 Postglacial erosion.---___-_--________-___---___-_-------__---__ 13 Creep-and-solifluction deposits and stone-banked terrace deposits. 14 Frost-wedged rock waste and boulders of disintegration........ 15 Landslides._______________________________________________ 19 Bog and swamp deposits. _______________________________"___ 20 Age of mass-wasting deposits--....----...--___---__---_--_. 20 References cited..____________________________ _____________________ 21 ILLUSTRATIONS [Plates in pocket] PLATE 1. Ice coverage and flow, Basin quadrangle, Jefferson, Lewis and Clark, and Powell Counties, Mont. 2. Interpretations of Pleistocene and Recent history, Montana and adjacent areas. FIGURE 1. Inferred limits of northern Boulder Mountains ice sheet, G-2 2. Typical rounded topography along Continental Divide in northern part of Boulder Mountains---.-,-.------ ------- 3 3.
  • West Antarctica: Tectonics and Paleogeography

    West Antarctica: Tectonics and Paleogeography

    Chapter 2 West Antarctica: Tectonics and Paleogeography The origin of West Antarctica (WANT) can be traced back to the Terra Australis orogenesis that began between 520 Ma and 510 Ma—shortly after the terminal suturing of Gondwana (Boger 2011). The onset of this event was responsible for the termination of passive margin sedimentation along much of the Pacific margin of Gondwana and marks the beginning of widespread and broadly coeval deforma- tion and arc-type plutonism. It also began a long-lived process of accretion that added much of the crust that defines eastern Australia, West Antarctica (domain 5 of Boger 2011, Fig. 2.1), and western South America (Cawood 2005, 2009). Post-Gondwana accretionary growth—the Terra Australis and Gondwanide Orogenies—The suturing of the West Gondwana and Australo–Antarctic plates along the Kuunga Orogen brought to an end the long-lived process of convergence between the pre-collision components of Gondwana. The result was a reconfigura- tion of the early to middle Cambrian plate system and the consequent transfer of ocean floor consumption from between the pre-Gondwana cratons to the outboard Pacific margin of newly formed Gondwana supercontinent (Cawood2005 ). This led to the establishment of the accretionary Terra Austrais Orogen (Cawood 2005), a general name given to the orogenic belt that stretched continuously from north- ern South America to northern Australia and which began in the early to middle Cambrian and lasted until the late Carboniferous. In Antarctica Terra Australis (Ross) orogenesis also deformed and variably metamorphosed the pre-Gondwana passive margin (Fig. 2.2). The Gondwana supercontinent underwent a sequential fragmentation over approximately 165 Ma.
  • ARC Centre of Excellence in Ore Deposits

    ARC Centre of Excellence in Ore Deposits

    Università degli Studi di Padova University of Tasmania DIPARTIMENTO DI GEOSCIENZE CODES - ARC Centre of Excellence in Ore Deposits ________________________________________________________________ SCUOLA DI DOTTORATO DI RICERCA IN: SCIENZE DELLA TERRA CICLO XXVI Jurassic magmatism in Patagonia, Mauritania and Mali: Examples of silicic and basaltic Large Igneous Provinces Direttore della Scuola: Ch.mo Prof. Massimiliano Zattin Supervisore: Ch.mo Prof. Andrea Marzoli Co-supervisore: Ch.mo Prof. Vadim Kamenetsky Dottorando: Lina Maria Serrano Duran ABSTRACT At the end of the Triassic and during Jurassic times, the Central Atlantic Magmatic Province (CAMP) with a dominant mafic composition, and the mainly felsic Patagonian Province (PA) were formed in the context of Pangea break-up. CAMP basaltic to basaltic-andesitic dykes and sills from Hank and Hodh, in Mauritania, and Kaarta, in Mali, were emplaced at ca. 197 Ma yielding a signature defined by low to high TiO2-values (0.39 - 2.29 wt.%), Nb-Ta troughs, Pb spikes and enriched Nd-Sr-Pb 143 144 87 86 207 204 compositions ( Nd/ Nd201Ma: 0.51224 - 0.51241, Sr/ Sr201Ma: 0.70572 - 0.70795, Pb/ Pb201Ma: 208 204 206 204 15.61 – 15.68 Pb/ Pb201Ma: 38.44 – 38.07 and Pb/ Pb201Ma: 18.11 – 18.48). Nb/U ratios (= 12 – 15), tracers of recycled material, combined with enriched isotopic signatures suggest the contribution of continental crust in the origin of these magmas. Differences in the ratios of La/Yb of the whole set suggest the existence of an enriched group in Kaarta (La/YbN>4.3) coupled to increasing ratios of Nb/Zr and Th/Y, probably reflecting lower degrees of partial melting in these rocks.